Apparatus for the production and utilization of undamped or sustained electrical oscillations.



No- 829,934. PATENTED AUG. 28, 1906. F. K. VREELAND.

APPARATUS FOR THE PRODUCTION AND UTILIZATION OPUNDAMPED OR SUSTAINBD ELECTRICAL;OSGILLATIONS.

APPLICATION FILED NOV. 14, 1906.

4 SHEETS-SHEET 1.

17 611 to? [Kg U412, Q

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No. 829.934 PATEN'I'EDAUG. 28, 1906.

'F. K. VRBELAND.

APPARATUS FOR THE PRODUCTION AND UTILIZATION OF UNDAMPED OR SUSTAINED ELECTRICAL OSOILLATIONSQ APPLICATION FILED NOV. 14. 1005.

4 SHEETS-SHEET z.

/ I efitor A l lomeys.

No. 829,934. PATENTED AUG. 28, 1906. F. K. VREELAND.

APPARATUS FOR THE PRODUCTION AND UTILIZATION OF UNDAMPED OR SUSTAINBD ELECTRICAL OSOILLATIONS.

APPLIOATION TILED NOV. 14, 1905.

4 SHEETS-SHEET 3.

Wz'tn esses PATENTED AUG. 28, 1906.

P. K. \ZREBLAND. I I APPARATUS FOR THE PRODUCTION AND UTILIZATION OF UNDAMPED- 0R SUSTAINED ELECTRICAL OSCILLATIONS.

APPLICATION FILED NOV. 14, 1905.

4 SHEETS-SHEET 4.

' IIOIZICVS' UNITED STAElfi PATENT OFFICE.

FREDERICK K. VREELAND, OF MONTCLAIR, NEW JERSEY, ASSIGNOR TO WIRELESS TELEGRAPH EXPLOITATION COMPANY, OF NEW N. Y. A CORPORATION OF NEW YORK.

APPARATUS FOR THE PRODUCTION AND UTILIZATION OF UNDAMPED OR SUSTAINED ELECTRICAL OSCILLATIONS.

Specification of Letters Patent.

Patented Aug. 28', 1906.

Original application filed February 28, 1905, Serial No. 247,826. Divided and this application filed November 14, 1906. Serial cillations of definite frefiency, and especially alternating currents of gh frequency, Without the aid of mechanical translating devices.

vplls Undam ed oscillations of low frequency may be obtained by mechanical means, but the frequency is limited by practical considerations governing the design and construction of the apparatus. Oscillations of higher frequency are desirable for man purposes, as is well known, and especially or the production of electromagnetic waves for use in wireless telegraphy, Wireless telephony, and for similar purposes. For this service low-frequency oscillations are unsuited owin to their small radiating power.

ere high-frequency currents are desired, it is usual to employ the free oscillations which may occur in a circuit containing capacity and inductance. A certain initial supply of energy is imparted to the oscillating system,.by charging the condenser, for example, andthis energy takes the form of alternating currents of a frequency determined by the electrical constants of the circuit, which alternating currents continue with constantly-decreasing amplitude until .all the energy is ex ended in radiation or in ohmic and other osses. Such oscillations are thus always damped, and their usefulness is therefore greatly limited.

By the apparatus herein described, the free oscillations of an electrical circuit are also utilized, but these oscillations are sustained by feeding energy into the circuit constantly or at intervals in synchronism with the oscillations to sup 1 that lost in radiation and otherwise, and tlius the oscillations are maintained at a constant amplitude as long as the supply ofenergy continues. This I accomby employing the energy of the oscillating circuit to produce, directly or indirectly, opposite or synchronous effects upon a sensitive gap or gaps which will be so related to the oscillating circuit as to supply energy thereto and malntain the oscillations. 'This may be done by the effect of a ma netic field upon a current in a solid or liqui conductor or in a rarefied gas or upon an 0 en or inclosed are, or by the effect of an e ectrostatic field upon the discharge of cathode particles in a vacuum-tube, or by the diversion of magnetic flux by the cross magnetomotive force of an auxiliary field, or by the direct effect of an electric current on the conductivity of the circuit in which it flows, or by other means of electrically commutating energy. I prefer to employ the effect of a magnetic field upon a sensitive gap or gaps formed by the electric current passing through one or more vacuum-tubes, such as mercury vapor tubes. This magnetic field may be directly. excited or have its excitation controlled by the electrical oscillations of the oscillating circuit,and its effect upon the vapor tube or tubes will be, according to one or another arrangement, to divert the current passing through the sensitive ap or gaps or to Vary'the conductivity of suc gap or gaps, so as to produce an electrical commutation of the current between different circuits which are related to the oscillating circuit, in such manner as to add energy thereto by this commutation in synchronism with the oscillations.

The invention may be carried out in many different ways and with a variety of forms of apparatus, some of which are illustrated in t e accompanying drawings.

Figure 1 illustrates in diagram an arrangement which I have found effective. In this 7 figure, 1 is a mercury-vapor tube; having anodes 2 3, and a mercury cathode 4. 5 is a source of direct current connected by .two branches 6 7 with the anodes 2 and 3 respectively. These branches 6 and 7 include large inductances 8 9 for maintaining a steady current. 10 is the oscillating circuit, containing a condenser 11. This circuit is shunted across the anodes 2 3, and includes the field coils: 1-2 18. It should be under- LStOO'd that'forisimplicity of illustration the field-coils 12 13 are shown with their axes in the plane of the anodes 2 3, while in practice they are laced in a plane perpendicular to that in w 'ch the anodes are located, so that the magnetic flux will be perpendicular to the plane of the anodes. In starting the apparatus, it is first necessary to establish the current across the sensitive gap formed by the tube 1. This may be done in any of the Wellknown Ways. At the start the current tends to divide e ually between the two parallel paths, but t ere is always some variation in. the distribution due to variable inequalities in the conductivities of the two paths. This is especially true when a mercury-vapor tube 7 is used. These irregular fluctuations are usually suflicient to start the oscillations; after which they give place to the periodic fluctuations controlled by the alternating 2o field; but where an additional impetus is required, this may be supplied by givin the condenser a sudden initial charge, by s ortcircuiting one ofthe inductances 8 9 and then suddenly removing the short circuit, or by otherwise disturbing the equilibrium of the s stem. When the magnetic field deflects the current in the tube, say from the anode 2 to the anode 3, the tendency is for the current in both branches 6 and 7 to pass wholly o or'largely through the tube from the anode 3 to the cathode 4, due to the fact that the path through, the tube from the anode 2 to the cathode 4 is interrupted or increased in resist ance by the deflection of the current toward 3 5 the anode 3. As the inductances 8 9 oppose any change in the current passing through them, this results in. the current in the branch 6 flowing through the oscillating circuit 10 from left to right, including both field-coils 12 13, thereby producing a field which still further deflects the current from 2 to 3. When the condenser is charged to the requisite potential, this current is checked and reversed, thereby producing a field in the op-' posite direction which deflects the current in the tube from the anode 3 to the anode 2. The result of this deflection is to cause the current in both branches 6 and 7 to pass through the tube from the anode 2 to the cathode 4, which results in the .current in the branch 7. flowing through the oscillating circuit from right to left and producing a current in the field-coils 12 13 which still further deflects the current from the anode 3 to the anode 2. In this way energyis supplied to the oscillating circuit insynchromsm with theoscillations. The frequency of these oscillations is dependent u on the constants of the oscillating circuit an may be changed by changing such constants.

The field-coils, instead of being connected in shunt to the anodes of the tube, may be connected in series therewith, as illustrated in Fig. 2 ,which is a diagram of the same character 65 as Fig. 1. In this arrangement the field-coils 12 and .1 3 are placed directly in the branch circuits 6 7 between the inductances 8 9 andthe anodes 2 3, and the oscillating circuit 10 is completed through these coils by connecting that circuit with the branches 6 7 between the field-coils 12 13 and the inductances 8 9. Extra inductances may be laced in the oscillating circuit, as shown. W en the magnetic field tends to deflect the current in the tube from the anode 2 to the anode 3, the current in the 7 5 branch 6 will be deflected through the oscillating circuit from left to right and will energize themagnetic field, producing a field tending to still further deflect the current from the anode 2 to the anode 3. The reversal of the current in the oscillating circuit will energize the magnetic field in the opposite direction, deflecting the current in the tube from the anode 3 to the anode 2 and causing the current in the branch 7 to pass 8 5 through the oscillating circuit from right to left, producing a still further energization of the magnetic field in the same direction.

Another arrangement is that illustrated in Fig. 3, which is a diagram similar to the fig ures already described, and in which a compound excitation of the magnetic field is provided. The oscillating circuit is shunted. across the anodes, as in Fig. 1, and is provided with the field-coils 12 13, while additional field-coils 14 15 are located in the branches 6 and 7. The direction of winding of coils 14 and 15 is such that their fields oppose and neutralizeeach other when they are traversed by equal battery currbnts. When the magnetic field tends to deflect the current from the anode 2'to the anode 3, the current in the branchfi asses through the oscillating circuit from eft to right, energizing the coils 12 13. The current in the coil 14 diminishes somewhat, and that in the coil 15 increases, thus adding to the magnetic eflect of coils 12 and 13. The resultant magnetic field tends to still further deflect the current to the anode 3. The reversal of the oscillating circuit reverses the field, deflects the current from anode 3 to anode 2, and causes the current in the branch 7 to flow through the oscillating circuit from right to left.

In Fig. 4 is shown a secondary series arrangement for the excitation of the field. A steadying inductance 16 is placed in the undivided portion of the battery-circuit. In the branches 6 and 7 are located oppositely- Wound rimar coils 17 18 of a transformer, of Whic 19 is t e secondary. The secondary coil 19 is located in the oscillating circuit 10, and the field-coil 20 is located in the oscillating circuit. The field-circuit is shown in this figure as in its proper relation to the plane of the anodes. The primar c'oils 17 18, being similar but being woun in opposite directions, an increasing current in 17 will have the same effect on the secondary 19 as a decreasing current in 18. The oscillating cur- 130 mary circuit.

rent in the circuit 10 will deflect the current in the tube from one anode to the other, so that the current from the battery will flow alternately in the two primary coils 17 and 18 of the transformer, and these variations in the primary current acting cumulatively on the secondary 19 induce'in the secondary the electromotive force necessary to overcome resistance and other losses and sustain the oscillations in the oscillating circuit 10. Either primary coil 17 18 may be used alone to excite the oscillating circuit, or each may act upon a separate oscillating circuit.

Many modifications of the arrangements shown in Figs. 1.to 4 may be employed.

In Fig. 5 an arrangement similar to Fig. 1

is shown, with the addition of another shuntcircuit 2 1 connected across the anodes 2 3, and containing condensers 22 23 and an inductance 24, forming an additional oscillating circuit. If the two oscillating circuits are tuned in unison, they will oscillate in parallel, and the circuit 21 may be used as the working circuit, while the circuit 10 serves only to excite the field. If the two oscillating circuits are not exactly in tune, there will be a wattless component of current leading in one circuit and lagging in the other according as the capacity reactance or the self-induction reactance preponderates. Thus by varying the constants of the two circuits any desired phase relation ma be secured between the current in the fie d-coils and the terminal electromotive force across 2 and 3, though usually it is desirable to have the electromotive force and the current in phase with each other.

In Fig. 6 is shown an arrangement in which the field-coils 12 13 are located in the oscillating circuit 10 connected inductively throu gh the transformer 25 26 to the pri- The primary 25 of the transformer is shunted across the anodes 2 3 and includes one or more condensers 27. The

condenser or condensers 27 permit the tuning of the primary circuit with respect to the secondary.

In Fig. 7 is shown an arrangement combining certain features of Figs. 4 and 6. The primaries 28 29 of a transformer are connected in series with the anodes 2 3, and a third primary 30, which may also include a condenser 31, is shunted across the anodes 2 3.

The secondary coil 32 is acted on cumulatively by all three of the primaries, and includes in its circuit the field-coils 12 13 and the condenser 11. a

Fig. 8 illustrates an arrangement similar to Fig. 4, but with the field-coils located in the .primary instead of in the secondary circuit.

The secondary current serves to control the frequency .of the field through the action of the secondary 19 on the primaries 17 18. The field-coil is divided into two sections 33 34 located respectively in the circuits 6 7.

v6 7. When, however, there is an unequal distribution of current in these circuits, the

field produced by one coil will predominate over that produced by the other, and will cause the current to be deflected to one or the other of the two anodes, as in the case illustrated in Fig. 4.

Instead of using a single vapor-tube with two anodes, two asymmetrical vapor-tubes 35 36 may be emplo ed', as illustrated in Fig. 9. 'Each of these tuhes has an anode 37 and a mercury-cathode 38, the anode of each tube being located atone side of the tube close to the cathode, so that when the current is div'erted by the magnetic field toward the anode, the current will flow in a short path from the anode to the cathode, while if the current isdefiected away from the anode, the current will follow a longer path and one of greater resistance. The arrangement of circuits for exciting the magnetic field shown in Fig. 1 is selected for illustration in Fig. 9, but any other arrangement may be employed. The cathodes of the'two tubes are connected together and with a source 5 of direct current. The circuit is divided into two branches 6 7, including large inductances 8 Qfand these branches 6 7 extend to the anodes of the two tubes. The oscillating circuit 10, including the condenser 11, is shunted across from one anode to the other, and includes the fieldcoils 12 13, one of which surrounds the tube 35 and the other the tube 36. The field'- coils 12 13 affect the tubes 35 36 oppositely.

When the current in the oscillating circuit 10 flows in one direction, it deflects the current in the tube 35 away from the short path between the anode and cathode, increasing the resistance of the path through which the current flows, while in the tube 36 the field deflects the current toward the short path between the anode and the cathode, thus giving the minimum resistance in this tube. The result of this is to cause the larger part of the current in the branch 6 to flow through the oscillating circuit from left to right, strengthening the fields in the direction to augment their effect upon the tubes. A reversal of the current in the oscillating circuit reverses the fields, and causes the path in the tube 36 to lengthen and increase in resistance, and the path in the tube 35 to shorten and decrease in resistance, with the result that the current in the branch 7 passes largely through the oscillating circuit from right to left, adding energy to the oscillating circuit and increasing the strength of the current in the field-coils.

The shifting of the current between paths of different lengths and resistances-is illu s trated in Fig. 10, in which the dotted line 39 illustrates the path that the current will take toward the anode, while the dotted line 40 shows the path that the current will take through the tube when the polarity of the field is reversed. The increased current density in the short path tends to still further increase its conductivity under suitable conditions.

A single asymmetrical tube may be employed to produce the electrical commutation of the current between two circuits, as illustrated in Fig. 11, in which the tube 41 is provided with the single anode 37 and the mercury cathode 38 placed close together on one side of the tube. The oscillating circuit 10, including the condenser 11, is shunted across the anode and cathode, and includes the field coil 42 surrounding the tube. The anode and cathode are also connected by another circuit, includn the source of direct current 5 and a steadying inductance. A plus current, for illustration, in the oscillating circuit and the field-coil Will deflect the discharge through the tube to the right, or cause it to follow the path of great length and resistance illustrated by the line 40 in Fig. 10. Since the battery current is made constant by the inductance, the increase in resistance of the path through the tube will force part of the current to pass through the oscillating circuit in shunt to the tube, and will increase the deflection of the current in the tube to the right, thus forcing more current throu h the oscillating circuit. When the con enser 11 is charged to a certain limiting point, its electromotive force will prevent a further flow of the current in this direction, and the current in the oscillating circuit will reverse, causing a deflection of the discharge to the left, or to the short path 39 shown inFig. 10. This reduces the resistance of the path throu h which the current passes in the tube, and allows an'increase of current from the anode to the' cathode, and a corresponding increase in the minus current in the oscillating circuit. The oscillations will thus be maintained.

The mercury-vs. or tube may be of a variety of forms, an preferably is one of suflicient size to give a considerable body of vapor for keeping the tube cool and the vacuum high during the operation of the apparatus. As illustrated in Fig. 12, it may be a tube of a substantially spherical shape, with the two anodes and cathode in its bottom. Or, as illustrated in Fig. 13, the anodes may be located at the ends of lateral tubes extending in opposite directions from the base of a chabmer, these lateral tubes increasing the resistance between the anodes and the cathode, and also increasing the potential necessary to operate the tube. Or, as shown in Fig. 14, the tube may be a ring-a construction which will give a wide defierence in resistance between the short path from one anode to the cathode, andthe long ath from that anode to the cathode around the other side of the rin A chamber could be added to the ring-tu e, if desired, to increase its vapor capacity. The

asymmetrical tube of Figs. 9 to 11 could be made in the form of any of these tubes with one of the anodes omitted or simply not utilized in making the circuit connections.

At the frequencies met with in ordinary alternating current practice, and even at very much hi her frequencies, an ordinary openair or inc osed arc may be used as the sensitive gap, such as is illustrated in Fig. 15, in which the parts are the same as described in connection with Fig. 4 except that the terminals 2, 3, and 4 of the vapor-tube are replaced by the carbon electrodes 2, 3, and 4 of an open or inclosed arc. Any of the other circuit arrangements described in connection with the vapor-tube having three terminals can be used with the three carbon electrodes.

Fig. 16 shows an arrangement in which a shunt oscillating circuit is caused to act upon two separate sensitive gaps similar to the arrangement shown in Fig. 9, but with electric arcs 43 44 substituted for the vapor-tubes. Adjacent to each arc is placed a block of carbon 45. A current in the field-coils 12 13 tends to deflect these arcs in opposite directions with respect to their carbon-blocks. Thus, the are 43 is deflected toward its block and its conductivity is not seriously diminished, while the are 44 is deflected into space and its conductivity decreases materially. These changes in conductivity are caused to excite the oscillations in the oscillating circuit 10 in a manner similar to that described with reference to Fig. 9.

With an arc such as illustrated in Fig. 16. conditions are secured similar to those secured with the asymmetrical vapor-tube of Figs. 9 to 11, and hence it follows that ueh an arc may be employed in an arrangement similar to that illustrated in Fig. 11. arrangement is shown in Fig. 17.

In the forms of apparatus above described, the sensitive gaps used have included a gas as the sensitive medium, but it is not necessary that the sensitive medium be gaseous. Simi- This lar results may be obtained by the use of a liquid or solid mediumfor example, the tubes which were described as containing mercury vapor may be filled with a conduct in liquid, or instead of the mercuryvapor tu e, a mass of solid material may be used having three terminals, the current entering through two of these terminals and leaving through the third, or vice versa. It is desirable to use a sensitive medium whose specific resistance is hi h, or to so construct the sensitive gap that t e act of commutation is accompanied by a considerable difference of potential between the terminals of the sensitive gap. This effect is promoted by the use crease that in the branch 47, thus starting a of a gaseous medium w ich, under suitable disturbance of the equihbrium 1n the oppoconditions of pressure, temperature, and ionization, has the property of rapidly increasing conductivity wlth increasing current density,

so that the effect of the concentration of current in a restricted path between one pair of electmdes is to greatly increase the conductivity of that path, while the conductivity of the other path is decreased. The result is a considerable for exciting t e oscillations. The effect of varying conductivity with varying current density may be in 'itself' sufficient under proper conditions to'maintain the oscillations. It is probable also that in a aseous medium the direct effect of ionic born ardment of the anodes contributes largely to the useful result. It evident, however, that the invention is notlimited to anyarticular method of producing the electrica commutation, or dependent upon any special theory of operation.

In Fig.18-is shown a form of apparatus inwhich the conductivity of the alternative arts is variedin a somewhat different manner.

. the conductingcolumn of gas in a vacuumtube. A vaccum-tube 46 is;provided with two protuberances 47, 48, in the ends of which are sealed anodes 49, 50. A single cathode 51 is provided near the center of the tube. Field-coils 52, 53 are wound around the protuberances 47, 48, and areconnected in the branches of .thedivided primary circuit, which include. the primaries I7, 18 acting on the secondary 19 of the oscillating cir cuit'10. When the current divides e ually between the two parallel paths throug the tube, the gas columns in the "protuberances 47, 48 willhave approximately e ual conductivities; but if the current in 52, or instance,

is greater than that in 53, the conductivity of the gas column in the branch 47 of the tube is diminished and a' still larger pro ortion of the current will be forced throug the gas column in the branch 48. This increase of current in the branch 48 the field-coil 52 and the primaryfll,andthecorresponding decrease in current in the branch 47 with the field-coil 53 and the primary 18, continue until a practically steady. state of ,unequal current distribution is reached, when the primaries 17 18 cease, to act on the secondary 19 and the current in the oscillating-circuit 1O reverses. This induces an electromo'tive force in the primaries 17, 18 (now acting as secondaries to the coil 19,) which tends to decrease the current in the branch 48 and inotential difference available fields acting .co letely interrupt the discharges, a set of auxiliary anodes 63,- 64 ma be provided, so.

site direction, and this process is repeated,

circuit is in shunt connection. The fieldcoils 52, 53are wound and connected to their res ective anodes 50 and'49, as in Fig. 18, an are connected respectively through the large steadyinginductances 8,9 to one terminal of the source 5. The oscillating cir cuit is connected in shunt across the coils 8, 9, so that any unequal distribution of current in the two branches of the tube will pro duce a current in the oscillating circuit, which is provided with an inductance 54. The current in the oscillating circuit is thus an alternating one, while the currents in the coils 52, 53 and their corresponding anodes and 49 are pulsating currents. These pulsating currents have the efiect of periodically diminishing the conductivity of the branches 47 and 48 of the tube alternately, as in the case illustrated in Fig. 18. I

It is not necessary'that the alternate paths should be'included in the same tube. 20 shows an arrangement in which two separate tubes 55, 56 are used. These tubes have anodes 57 58 and cathodes 59, 60, and are provided with field-coils 61, 62, which are con-. nected at one end with one terminal of the Fig.

direct-current source, and at their other ends V are connected with the primary coils 17, 18, actin upon the secondary coil 19 in the oscillating circuit 10. "Chan es in the conductivities of the gas columns in the tubes 55,56 .will act in a manner similar to that described in'reference-to Figs. 18v and 19.: In case the on the tubes are sufficient to placed as to be uninfiuence by the field, and connected through steadyinginductances 65,

66 with the source of ower. These auxiliary anodes will keep t I e cathode resistancebroken down, so that the current through the main anodes 57, 58 will start again at the proper time. The steadying inductance 16 may then be omitted, if desired. A single tube of this'character having only one anode may be employed to produce the oscillations. This is illustrated in Fig. 21, in which the tube 67 is provided with two field-coils 68, 69, the former being in'series with the source of current 5 between the anode and the cathode, while the latter is in the oscillating cirrent to flow in 69.

, of the gas'column and still further increase the minus current in 69. The periodic reversals of the oscillating circuit will, as al ready explained, produce the reversal of current in the coil 69.

In Fig. 22 the variable anode-current is used to excite the field 68. As its variations are just the opposite to what is required, an auxiliary field 69 fed by a constant source 70 is o posed to and is greater than 68. The difl erential eiiects of 68 and 69 give the required result.

An alternating current, either single phase or polyphase, may be used instead of a direct current to feed the ap aratus. Fig-23 shows the apparatus supp ied by a three -phase current. 1 is the vapor-tube, having a single cathode 4, and provided with six anodes, three of which 71, are located on one side of the tube, and the other three, 72, on the other side of the tube. These anodes are connected to separate primaries 73,74 of a transformer, whose secondary 19 is located in the oscillating circuit 10 containing the condenser 11 and the field-coil 20. The priemaries 73 are Wound in the same direction, so that their efiects on the secondary 19 are similar, and the primaries 74 are wound in the opposite direction. The primaries 73 and 74 are connected in parallel in pairs, and each pair of the primaries is in series in circuit with one phase of a three-phase alternating-current generator 75, whose neutral point is connecte through the steadying resistance 16 to the cathode 4 of the tube. The mode of operation of the apparatus is similar to that ot the apparatus shown in Fi 4. The vacuum-tube acts as a rectifier 0 the alternatin current by permitting the current to flow on y in one direction, 4 e., from'one or more of the anodes to the cathode, the 0 posite half-wave being excluded; and tl ie sum of the half-Waves in the three phases is equivalent to a direct current of nearly steady value The fluctuations of this equivalent direct current being of low frequency, will not have any ap reciable effect on the secondary 19, b t t e deflection of the current from one of t e anodes 71 to the corresponding anode 72 will produce an effect on the secondary similar to that which occurs in the case of the direct current in Fig. 4.

Fi". 24 shows the apparatus fed b a single-'p ase alternating current. In t 's case the tube 1 is provided with two anodes 2, 3, and the cathode 4, as in Fig. 4, the anodes bein connected with the primaries 17, 18-, whic are connected in parallel with the source 76 of singlebase alternatin current, the other pole ofwhich is connecte through the inductance 16 with the cathode 4. In this case the inductance 16 should be small enough to permit the ready passage of the alternating current from the source, or in some cases the inductance may be omltted altogether. As the sin le-phase alternating current when rectified y the tube 1 is-dlscontinuous, it is necessary to supply means for starting the current through the tube at the beginnin of each eflective half-wave. To accomplis this, it is sufficient to keep the cathode resistance, which is high at starting, continuously broken down by means of a small electric current supplied by a, local source 77 through a steadyin -inductance"78 and an auxiliary anode 79. lhe alternating current will then start readily when the electromotive force is applied in the proper direction. When a single-phase alternating current is used, the suppl of energy is intermittent; consequently t e currents in the oscillatin circuit 10 will be intermittent unless the amping of this circuit is so small that its oscillations may persist through the period of inactivity of the source. This feature possesses certain advantages when the apparatus is used as a transmitter in wireless telegraphy, as it causes the signals to be broken up into individual impulses recurring at the frequency of the alternating current, each impulse-consisting of a train of Waves of practically constant amplitude. Signals of this character are particularly desirable when the sign als are received by ear, as an intermittent impulse gives a much stronger physiological effect than a continuous impu se. This feature is also advantageous in imparting a distinctive ,character to the radiations apart from their definite wave frequency, which enables them to be distinguished from signals from another source either audibly or by means of some automatic selecting apparatus.

A quarter-phase alternating current can be used in the same manner as a single-phase current by'using two pairs of anodes and primaries instead of one; or it ma be converted into a four-phase current in t e well-known way, and used with four sets of anodes and primaries 111 8. manner-similar to that illustrated for three-phase currents in' Fig. 23. In the former case the energy supply will be intermittent, and in the latter continuous thou h'variable.

ether the alternating-current supply be single phase or polyphase, it is desirable to have two sets of apparatus of the character illustrated in Figs. 23 and 24, having their polarities reversed with respect to the source of power. The second set of apparatus will then use the half-waves of the alternating current that are rejected by the first set. The two sets of apparatus may operate separate oscillating circuits, their respective primary coils being made to act on separate secondary coils, or they may be caused to act cumulatively on a single oscillatin circuit. Fig. 25 shows an arrangement in W ich this is accomplished by causing the primary coils of the two systems to act on a single secondary. The case illustrated is that in which a single-phase alternatin current is used. The primary coils 80, 81 o the first system are wound respectively in the same direction as the primaries 82, 83 of the second system, so that the two systems w ll act in the same sense and therefore cumulatively on the secondary 19, and the field-coils 12, 13 included in the oscillating circuit 10 are wound to have similar effects on the two tubes.

So far I have described only the method of and apparatus for producing the -|scillations. They may be utilized in many ways; for example, in electrotherapeutics, in exciting high-frequency discharges in vacuum-tubes for lighting, in producing high potential effects through the agency of air core-transformers, and for many other purposes for which alternating currents, whether of extremely high or of lower frequencies, are desirable. They are especially useful in a transmitter for use in wireless telegraphy or wireless telephony. For this urpose the'oscillating circuit may be coup ed to a radiating antenna in any one of several well-known ways.

In Fig. 26 the oscillating circuit 10 is illus-. trated as supplied with energy by the are rangement of apparatus shown in Fig. 1. This oscillating circuit includes the primary 84 of a step-up transformer, whose secondmy 85 is connected in series with the antennacircuit 68, which is suitably tuned with respect to the primary circuit. Theradiation is made intermittent at will for the purpose of producing signals by means of a key 87 wlnch short-circuits the rimary 84 of the step-up transformer and thus annuls its action on the antenna-circuit.

Another arrangement is shown in Fig. 27, in which the key 87 is placed in a tertiary circuit 88 of the ste -up' transformer. The closing of the key s ort-circuits the tertiary circuit and annu s the inductive effect of the primai'y 84 on the secondary 85.

In ig. 28 the key 87 isplaced so as to short-circuit an auxiliary inductance 89, placed in the oscillating circuit "10. In this arrangement the radiation of energy from the antenna is continuous, but its frequency is altered by the presence or absence of the auxiliary inductance 89 in the oscillating circuit, and the. latter is thus thrown in or out of tune with the antenna-circuit and with the receiving apparatus, which is assumed to be tuned to respond onl to a given frequency of the transmitter. nstead of throwing the oscillating circuit in and out of tune with the antenna by changing the inductance of the circuit, the same result may be secured. by

the exciting-circuit.

changing the capacity of the oscillating circuit, as. by opening and closing a circuit through an auxiliary condenser 91 by means of a key 92. I

For wireless telephony it is preferable to employ an arrangement such as is shown in Fig. 29, in which the working oscillating circuit is separate from the oscillatim circuit which excites the field, as illustrated in Flg. 5. The inductance 24 of Fig. 5 is utilized as the primary of a step-up transformer, whose secondary is in the antenna-circuit. The tertia of the transformer is closed by a carbon te ephone-transmitter 90, having a sufficient current-carrying ca acity to answer the purpose. 1 Any of tlie arrangements which have been described for producing the oscillations may be employed for utilizing such oscillations in any of the ways shown in Figs. 26 to 29.

The arrangement in which a separate working circuit is used in shunt with the excitmgcircuit is particularl eflective in wireless si aling and especial yin wireless telephony. T e period of the exciting-circuit determines the frequency of the oscillations, while the natural period of the working circuit determines the intensit of its oscillations. The latter are free osci lations of large amplitude when the two circuits are in time, and a'small variation in the electrical constants of the circuit will cause the resulting forced oscillations to fall off greatly in am litude. Thus the radiation may be control ed by cutting in or out inductance or capacityan operation which in this arrangement involves a small expenditure of energy and hence no special precaution for handling a large current. Thus a simple key of small size or a carbon telephone-transmitter may be used effectively. A similar result may be obtained by va ing'the electrical constants of A further advantage of this arrangement is in the fact that the intensity and frequency of the exciting-current is practically independent of the amount of ener that is being drawn from the apparatus. he apparatus thus works in much the same manner as a shunt-dynamo, taking energy from the source of power in propor-- tion to the energy expended in the working circuit. Where it is desired to increase the excitation with increasing output, a com' pound field, such as is illustrated in Fig. 3, may be used. The working circuit is not necessarily a tuned circuit; for some puroses an aperiodic circuit may be substituted or the tuned Working circuit.

This application is a division of my application, ,Serial No. 247,826, filed February 28, 1905 in which the method herein described is claimed.

What I claim is- 1. An apparatus for producing electrical oscillations, wherein are combined an elecoscillations, wherein are combined an electrical oscillating circuit, a field excited or controlled by the oscillations of such circuit, a sensitive gap or gaps acted upon by such field to electrically commutate energy therein, and means for adding by such commutation increments of energy to such oscillating circuit.

3. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a ma netic field excited or Controlled by the oscil ations ofsuch circuit and acting to electrically commutate energy, and means for adding by such commutation increments of energy to such oscillating circuit.

4. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillatin circuit, a ma netic field excited or control ed by the osci lations of said circuit, a sensitive gap or gaps acted on by said magnetic field to electrically commutate energy therein, and means for adding by such commutation increments of energy to such oscillating circuit.

5. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a field excited or controlled by the oscillations of said circuit, a gaseous medium acted upon by said field to electrically commutate energy therein, and means for adding by such commutation increments of energy to such oscillating circuit.

6. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a field excited or controlled by the oscillations of said circuit, a rarefied aseous medium acted upon by said field to e ectrically commutate energy therein, and means for adding by such commutation increments of energy to such oscillating circuit.

7. An apparatusfor producing electrical oscillations, wherein are combined an electrical oscillati circuit, a magnetic field excited or contro ed by the oscillations of said circuit, a gaseous medium acted upon by said magnetic field to electrically commutate current therein, and means for adding by.

adding by such commutation increments of energy to such oscillating circuit.

9. An apparatus for producin electrical oscillations, wherein are combine a variable magnetic field, two or more alternative circuits the conductivity of one or more of which is periodically altered by the influence of. such variable magnetic field thereby causing a periodic variation in the currents in said circuits, means for exciting oscillations of definite frequency by these variable currents, and means for controlling the variations of the magnetic field by such oscillations.

10. An apparatus for producing electrical oscillations, wherein are combined a variable magnetic field, two or more alternative circuits the conductivity of one or more of which is periodically altered by the influence of such variable magnetic field, thereby causing a periodic variation in the currents in said circuits, means for controlling the variation of such magnetic field by such currents, and a circuit or circuits operatively connected with the system and controlling by means of capacity and inductance the frequency of the variations in said currents.

11. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a sensitive medium through different paths in which an electric current passes, means for electrically commutating the current in such different paths, and means for adding by such commutation increments of energy to such oscillating circuit.

12. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a gaseous medium through dilierent paths in which an electric current passes, means for electrically commutating the current in such difierent paths, and means for adding by such commutation increments of energy to such oscillating circuit.

13. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a plurality of similar paths or circuits, means for electrically commutating the energy in such similar paths or circuits in synchronism with the oscillations of the oscillating-circuit, and means for adding by such commutation increments of energy to the oscillating circuit.

14. An apparatus orproducing electrical oscillations, wherein are combined an electrical oscillating circuit, a plurality of similar paths or circuits, means for electrically commutating electrical currents in such similar paths or circuits, and means for adding by such commutation increments of energy to the oscillating circuit.

15. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, two similar parallel circuits, means for electrically commutating electrical currents in said similar parallel circuits in synchronism with the Oscillations of such oscillating circuit, and means for adding by such commutation increments of energy to the oscillating circuit.

16. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a sensitive medium through difi'erent paths in which an electric current passes, a magnetic field affecting the current in such paths in synchronism with the oscillations of such oscillating circuit,

thereby electrically conimutating said current, and means for adding by such commutation increments of energy to such oscillating circuPt.

17. An apparatus for producing electrical oscillations, wherein are combined an elec trical oscillating circuit, a gaseous medium through different paths in which an electric current passes, a magnetic field affecting the current in such paths in synchronism with the oscillations of such oscillating circuit, thereby electrically commutating said current, and means for adding by such commutation increments of energy to such oscillating circuit.

18. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circui t a vapor tube or tubes through different paths in which an electric current passes, a magnetic field affecting the current in such paths in synchronism with the oscillations of such oscillating circuit, thereby electrically commutating said current, and means for adding by such commutation increments of energy to such oscillating circuit.

19. An apparatus for producing electrical oscillations. wherein are combined an electrical oscillating circuit, a sensitive medium through different paths in which an electric current passes, an alternating magnetic field oppositely and alternately affecting the current in such paths to commutate the electric current in such medium, means for adding by such commutation increments of energy to such oscillating circuit, and means for controlling the alternating magnetic field by such oscillations.

20. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a gaseous medium through different paths in which an electric current asses, an alternating magnetic field opposite y and alternately afiecting the current in such paths, thereby commutating said current, means for adding by such commutation increments of ener y to such oscillating circuit, and means for controlling the alternating magnetic field by such oscilia tions.

21. An apparatus for producing electrical oscillations, wherein are combined an elecalternating magnetic field by such oscilla-' tions. .7

, 22. An apparatus for producmg electrical oscillations, wherein are combined an electrical oscillating circuit, two channels in which a comparatively steady current is established connected with such circuit, a sensitive gap in each channel shunted by said circuit, and a magnetic field controlled by the oscillations in such circuit for producing opposite effects upon the current in the two gaps to divert current alternately from said channels through said oscillating circuit.

23. An apparatus for producing electrical oscillations, wherein are combined an oscil lating circuit, two channels in which a comparatively steady current is established connected with such circuit, a sensitive gap in a gaseous medium included in each channel and shunted by said circuit, and a magnetic field controlled by the oscillations in such circuit for producing opposite effects upon the current in the two-gaps to divert current alternately from said channels through said oscillatin circuit.

24. in apparatus for producing electrical oscillations, wherein are combined an oscillating circuit, two or more alternative circuits through which an electric current passes, a sensitive gap or gaps in said alternative circuits, an alternating magnetic field whose flux is perpendicular to the current in said gap or gaps for periodically diverting the current therein, thereby electrically commutating the current insaid circuits, means for adding by such commutation increments of energy to said oscillating circuit, and means for controlling the alternating magnetic field by such oscillations.

25. A11 apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, two alternative circuits through which an electric current passes, a sensitive gap in each of said alternativecircuits, an alternating magnetic field whose flux is perpendicular to the flow of current through said gaps for diverting the current in said aps alternately and oppositely, thereby e ectricaily commutating the current in said circuits, means for adding by such commutation increments of energy to said electrical oscillating circuit, and means for controlling the alternating Blfi-gfl62l10 fie d by such oscillations.

26. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a sensitive medium through two adjacent paths in which an electric current passes, an alternating magnetic field whose flux is perpendicular to the plane .of said paths for diverting the current in said paths alternately and oppositely, thereby commutating the current in said paths, means for adding by such commutation increments of energy to said electrical oscillating circuit, and means for-controlling the alternating magnetic field by such oscillations.

27. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a Va or-tube through two adjacent paths in whic an electric current passes, said tube being provided with two anodes and a single cathode, an alternating magnetic field acting on said tube and whose flux is perpendicular to the plane of the electrodes of the tube for diverting the current in said paths alternately and oppositely, thereby electrically commutating the current between the two paths in the tube, means for adding by such commutation increments of energy to said electrical oscillating circuit, and means for controlling said alternating field by such oscillations.

28. An apparatusfor producing electrical oscillations, wherein are combined an electrical oscillating circuit, a magnetic field controlled thereby for commutating an electric current, a working circuit in parallel with the controlling oscillating circuit, and means for supplying to said working circuit the oscillations produced by said controlling oscillating circuit.

29. An apparatus for producing electrical oscillations, wherein are combined an electrical oscillating circuit, a magnetic field controlled thereby for commutating an electric current, a second or working oscillating circuit in parallel with and tuned to the same frequency as the controlling oscillating circuit, and means for supplying to said second or working oscillating circuit the oscillations produced by said controlling oscillating circuit.

30. An apparatus for producing electrical oscillations of variable intensity, wherein are combined an electrical oscillating circuit, a magnetic field controlled thereby for commutating an electric current, a second oscillating circuit, means for impressing such 0scillations on said second oscillating circuit, and means for controlling the intensity of the oscillations by varying the electrical constants of one or both circuits.

31. An apparatus for producing electrical oscillations of variable intensity, wherein are combined a generator of sustained electrical oscillations, a resonant circuit, means for impressing such oscillations on said resonant circuit, and means for controllin the intensity of the oscillations in sai circuit by throwing the circuit in and out of tune with the generator.

eizael 32. An apparatus for producing electrical-- oscillations of variable intensity,-.wherein are combined a generator of sustained electrical oscillations, a resonant circuit, means for impressing such oscillations on said resonant circuit, and means for controlling the intensity of the oscillations by varying the electrical constants of-pne or both parts of the system by shunting capacity or inductance.

33. An apparatus for producing electromagnetic waves, .wherein are combined an electrical oscillating circuit, different paths in a sensitive .medium through which paths an electric current passes, means for electrically commutating the current in said paths, means for adding by such commutationincrements of energy to such oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

34. An apparatus; for producing electro magnetic waves, wherein are combined an electrical oscillating circuit, diiierent paths in a gaseous medium through which an electric current passes, means for electrically commutating the current in such paths, means for adding by such commutation increments of energy to such oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

35. An apparatus for producing electromagnetic waves, wherein are combined an oscillating circuit, a plurality of similar paths or circuits, means for electrically commutating energy in such similar paths or circuits inoscillating circuit, 'a radiating circuit, and.

means for impressing such oscillations upon said radiating circuit.

36. Ail apparatus for producing electro magnetic waves, wherein are combined an electrical osclllatmg circuit, a plurality of similar paths or clrcuits, means for electrically commutating electrical currents in such.

similarpaths or circuits in synchronism with the oscillations of such oscillating circuit, meansifor adding by such commutation increments of energy to such oscillating circuit, aradiating circuit, and means for impressing such oscillations upon said radiating circuit.

37. An apparatus for producing electromagnetic waves, wherein are combined an electrical oscillating circuit, two similar parallel circuits, means for electrically commutating electrical currents in said parallel circuits in synchronism with the oscillations of such oscillating circuit, means for adding by such commutation increments of energy to such oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

38. An apparatus for producing electrocuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

39. An apparatus for producing electromagnetic waves, wherein are combined an electrical oscillating circuit tuned to a high frequency, afield excited or controlled by the oscillations of said circuit, a sensitive gap or gaps acted upon by said field to electrically commutate energy therein, means for adding by such commutation increments of energy to such oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

40. An apparatus for producing electromagnetic waves, wherein are combined an electrical oscillating circuit tuned to a high frequency, a magnetic. field excited or controlled by the oscillations of said circuit and acting upon an electric current to electrically commutate said current, means for adding by such commutation increments of energy to said electrical oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

41. An apparatus for producing electromagnetic waves, wherein are combined an electrical oscillating circuit tuned to a high frequency, a magnetic field excited or controlled by the oscillations of said circuit, a sensitive gap or gaps, the electric current in said gap or gaps being acted upon by said field to electrically commutate the energy in sudh gap or gaps, means for adding by such commutation increments of energy to said electrical oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

42. An apparatus for producing electromagnetic waves, wherein are combined an electrical oscillating circuit tuned to a high frequency, a magnetic field excited or controlled by the oscillations of said circuit, a gaseous medium, the electric current in such medium being acted upon by said field to electrically commutate said current, means for adding, by such commutation increments of energy to said electrical oscillatingcircuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

43. An apparatus for producin electro magnetic waves, wherein are com ined an electrical oscillating circuit tuned to a high frequency, a magnetic field excited or controlled by the oscillations of said circuit, a

vapor tube or tubes, the electric current in such tube or tubes being acted upon by said field to electrically commutate said current,

means for adding by such commutation increments of energy to said electrical oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

44. An apparatus for producing electromagnetic waves, wherein are combined an oscillating circuit tuned to a hi h frequency, a sensitive medium through different paths in which an electric current passes, a magnetic field affecting the current in such paths in synchronism with the oscillations of such oscillating circuit to electrically commutate said current, means for adding by such commutation increments of energy to said oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said rediating circuit.

-15. An apparatus for producing electromagnetic waves, wherein are combined an oscillating circuit tuned to a high frequency, a, gaseous medium through different paths in which an electric current passes, a magnetic field afiecting the current in such paths in synchronism with the oscillations of such oscillating circuit to electrically commutate said current, means for adding by such commutation increments of energy to said oscillating circuit, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

46. An apparatus for producing electromagnetic Waves, wherein are combined an oscillating circuit tuned to a high frequency, a sensitive medium through different paths in which an electric current passes, an alternating magnetic field oppositely and alternately affecting the current in such paths to commutate the electric current in such medium, means for adding by such commutation increments of energy to said oscillating circuit, means for controlling the alternating magnetic field by such oscillations, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

47. An apparatus for producing electromagnetic waves, wherein are combined an oscillating circuit tuned to a high frequency, a gaseous medium through different paths in which an electric current passes, an alternatin magnetic field oppositely and alternatelya ecting the current in such paths to electrically commutate said current, means for energy to said oscillating circuit, means for controlling the alternating magnetic field by such oscillations, a radiating circuit, and means for impressing such oscillations upon said radiating circuit.

48. An apparatus for the wireless transmission of intelligence, wherein are combined adding by such commutation increments of an. electrical oscillating circuit, difierent paths in a sensitive medium through which an electric current passes, means for electrically commutating the current in such different .paths, 'means for adding by such commutations to convey intelligence.

, which an electric current varying the character or intensity 0 there 49. An apparatus for the wireless transmission of intelligence, wherein are combined an electrical oscillating circuit, different paths in a gaseous medium through asses, means for electrically commutating t e current in such different paths, means for adding by such commutation increments of energy to such oscillating circuit, a radiating circuit, means for impressing the oscillations upon said radiatin circuit and means for interru tin or diations to convey intelligence.

50. An apparatus for the wireless transmission of intelligence, wherein are combined an electrical oscillating circuit, a'plurality of similar'paths or circuits, means for electrically commutating energy in saidsimilar' paths or circuits in synchronism withthe oscillations of such oscillating circuit, means, for adding by such commutation increments of energy to such oscillating circuit, a radiating circuit, means for impressing such oscil-.

lations upon said radiating circuit, and means for interrupting or varying the'character or intensity of the radiations to convey intelligence.

51. An apparatus for the wireless transmission of intelli ence, wherein are combined an electrical osci lating circuit, a lurality of similar paths or circuits, means or electrically commutating electrical currents in said similar paths or circuits in synchronism with the oscillations of such oscillating circuit, means for adding by such commutation increments of energy to such oscillating circuit, a radiating circuit, means for impressing such oscillations upon said radiating circuit, and means for interrupting or varying the character or intensity of the radiations to convey intelligence.

52. An apparatus for the wireless transmission of intelligence, wherein are combined an electrical oscillating circuit, two similar parallel circuits, means for electrically commutating electrical currents in said similar parallel circuits in synchronism with the oscillations of such oscillating circuit, means for, adding by such commutation increments of energy to such oscillating circuit, a radiating circuit, means for impressing such oscillations upon said radiating circuit, and means for interru ting or varying the character or intensity 0? the radiations to convey intelligenc'e. T 53. An apparatus for'the wireless transmission of intelligence, whereinare combined see, 934

an electrical oscillating circuit, a field excited 6 5 mission of intelligence, wherein are combined an electrical oscillating circuit, a magnetic field controlled thereby for commutating an electric current to roduce lectrical oscil-' lations, a radiating circuit, means for impressing such oscillations upon said radiating circuit,-and means for interrupting or varying the character or intensity of the radiations to convey intelligence.

55. An apparatus for the wireless transmission of intelligence, wherein are combined an electrical oscillating circuit, a magnetic fieldcontrolled thereb for commutating an electric current where y sustained electricaloscillations are continuously generated, a radiating circuit, means for impressing such oscillations upon said radiating circuit, and means for interrupting or varying the character or intensity of the radiationsto convey intelligence.

56. An apparatus for the wireless transmission of intelligence, wherein are combined an electrical oscillating circuit, a magnetic field controlled thereb for commutating an electric current where y sustained electrical oscillations are continuously generated, a radiating circuit, means for impressing such oscillations upon said radiating circuit, and

means for interrupting or varying the character or intensity of the radiations by varying the-electrical constants of the system to convey intelligence.

57. An apparatus for the wireless transmission of intelligence, wherein are combined two oscillating circuits, a radiating circuit, means for impressing u on said radiating circuit the electrical osci lations set up in said oscillating circuits, means for controlling the frequency of the radiations by one oscillating circuit, and means for controlling the inten sity of the radiations by varying the electric al constants of one or both oscillating circuits. 58. An apparatus for the wireless transmission of intelligence, wherein are combined two electricaloscillating circuits, a magnetic field for commutating an electric current whereby sustained electrical oscillations are continuously generated in said system of circuits, means for controlling the rate of commutation by the oscillations of one of the oscillating circuits, a radiating circuit, means for impressing the oscillations of the other oscillating circuit-uponsaid radiating circuit,

mission of intelligence, wherein are combined a generator continuously generating sustained electrical oscillations, a resonant circuit,

means for impressing such oscillations on said resonant circuit, means for exciting electromagnetic radiations by the oscillations in the resonant circuit, and means for conti olling the intensity of the radiations by throwing the resonant circuit in and out of tune with the generator.

60. An apparatus for the wireless transmission of intelligence, wherein are combined a generator of sustained electrical oscillations, a' resonant ing ,such oscillations on said resonant circuit, means for exciting electromagnetic radiations by the oscillations in the resonant circuit,means for impresscircuit, and means for controlling the intensity of the radiations by varying the relative frequency of the generator and the resonant circuit.

61. An apparatus for the wireless transmission of intelligence, wherein are combined a generator of sustained electrical oscillations, a resonant circuit, means for impressing such oscillations on said resonant circuit, means for exciting electromagnetic radiations by the oscillationsin'the resonant circuit, and means for controlling the intensity of the radiationsby shunting capacity or in ductance.

This specification signed and witnessed this 9th day of November, 1905.

FREDERICK K. VREELAN D.

Witnesses AUG. LONG, J OHN S. LOTSCH. 

